Traditional vibration analysis of machinery typically requires measurements to be made under constant operating conditions. For example, to achieve repeatability and trendability, data collection is usually done while the machinery is operating at steady state and constant speed, with unchanging load, without acceleration or deceleration, and with a single direction of movement for each component of the machinery.
However, some types of articulating machinery, such as shovels and draglines used in heavy excavation and mining, do not operate under steady-state conditions. Instead, they experience frequent changes in direction with variable speed, variable acceleration/deceleration, and variable loading. Movements such as hoist up, hoist down, crowd out, crowd in, swing left and swing right, all require changing and reversing direction, speed, acceleration, and deceleration.
Within some of these articulating machines are constant-speed and constant-load rotating assets, such as cooling fans and hydraulic pumps. Although these support components are typically not as critical as the articulating components, if the support components fail, the critical assets may overheat or have no fluid pressure to drive the articulating components, thereby shutting down operation of the articulating machine.
The widely-varying loads experienced by shovels and draglines and other types of heavy articulating machinery can stress their structures to the point of fatigue and eventual failure. The complex signatures attributable to variable power, variable load, changing speeds, and many other signature-producing actions associated with articulating machinery make it extremely challenging to achieve repeatable, trendable and meaningful vibration measurements for use in monitoring the condition of articulating and reciprocating machinery.
What is needed, therefore, is a system for achieving repeatability and trendability in vibration data collected from articulating and reciprocating machinery.